Field of Invention
The present invention relates to a variable geometry turbo system in which a turbine is rotated by exhaust gas, and a compressor rotated by the turbine compresses intake air to increase an output of an engine and improve the quality of exhaust gas.
Description of Related Art
Turbo chargers are widely used in internal combustion engines and in the past were particularly applied to large-sized trucks or ship engines. In recent years, turbo chargers have been used in passenger vehicles in order to produce high output in smaller engines. Turbo chargers more fully combust fuel to improve the quality of exhaust gas. Various functions and designs of turbo chargers are disclosed in prior art.
In addition, a turbo charger generally includes a turbine rotated by the exhaust gas and a compressor rotated by the turbine to compress intake air, and has a structure in which a shaft connects the turbine and the compressor.
Existing variable geometry turbo chargers include a vane base ring and a vane cover ring with a variable vane interposed therebetween and a stud or a sleeve is adopted in order to keep a predetermined interval between the vane base ring and the vane cover ring.
Other prior art variable geometry turbo chargers experience the problem that the stud or the sleeve that keeps the predetermined interval between the vane base ring and the vane cover ring is one of the factors that increase exhaust resistance thereby decreasing efficiency. The stud or sleeve also increases the number of parts and a weight of the system thereby further decreasing engine efficiency.
Therefore, what is needed is a variable geometry turbo charger with reduced weight which can still effectively reduce resistance due to the exhaust gas flowing through the variable vanes.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information fully describes the prior art that known to a person skilled in the art.